This invention relates to a system and process for recovering solar energy and its utilisation, particularly but not exclusively for heating installations, for the production of a hot fluid (such as water for consumption) and for other civil and industrial applications wherever preheating, even at low levels, is possible in the course of a thermal process.
The disadvantages inherent in heating systems of the traditional combustion type are known, and the need to utilise other sources of clean energy, in particular solar energy, to obviate these is increasingly felt.
Thermal solar energy systems comprise a collector or absorber arranged to intercept the radiant solar energy and raise the temperature of a working fluid which gives up heat by passing through suitable heat transmission means, such as radiators of central heating installations, heating banks, water heaters, boilers, heat exchangers and the like.
In known systems, this working fluid, heated by an intermediate fluid from the solar collector, is available in storage tanks which are supplemented thermally by a source of traditional heat, and from which the fluid is drawn according to requirements. This indirect system leads to problems of low temperature heat exchange with consequent slowness on starting and heat losses which negatively influence the thermal efficiency of the system.